Lille's seven-game winning away streak in Ligue 1 ended with a dour 0-0 stalemate at AS Monaco on Sunday as the pacesetters dropped precious points in the title race.
The northerners, who now have 63 points from 29 games, extended their advantage over second-placed Paris St Germain to three points, but their lead will be wiped out should the reigning champions beat visiting Nantes in the late game.
Monaco are fourth on 56 points, four behind Olympique Lyonnais, who were held to a 1-1 draw at Stade de Reims on Friday.
Monaco and Lille had just four shots on target between them in the match and failed to create decent chances, eventually looking content with a point, although Stevan Jovetic was denied by Lille keeper Mike Maignan's superb save in stoppage time.
Earlier, RC Lens and Metz, both promoted from Ligue 2, drew 2-2 at Felix Bollaert to stay sixth and seventh respectively.
Lens have 45 points and trail fifth-placed Olympique de Marseille, who beat Stade Brestois 3-1 on Saturday, on goal difference. Metz have 42 points.